This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-023362, filed Jan. 31, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a disk drive and particularly to a security technology using a hidden storage area provided on a disk storage medium.
2. Description of the Related Art
In recent years, particular attention is paid to the information service system which distributes content data such as images (motion and still pictures), sound, etc. or programs from the Internet or digital broadcasting networks. In such a system, distributed data is downloaded to digital devices including a personal computer and is saved in a storage medium installed on the digital device. Digital devices include a digital television, a PDA (personal digital assistant), a portable telephone, and a mobile reproduction device, etc.
The storage medium installed on the digital device can be a memory card comprising flash EEPROM or disk drive such as a hard disk drive (HDD) or a magnet-optical disk drive (MO drive).
The information service system must use the security feature for protecting the copyright of content data or programs, especially for copy protection. This security feature includes an authentication feature which specifies part of storage medium areas as a hidden storage area for performing authentication when the hidden storage area is accessed. When an access request is issued to the hidden storage area, the authentication feature executes an authentication process for determining whether to permit the access.
Conventionally, security systems including various authentication methods are developed for a system using a memory card e.g. comprising flash EEPROM. By contrast, a system using a disk drive such as an HDD provides various security systems for a host system (digital device itself), but offers limited security features for the disk drive itself.
The security feature applied to the conventional disk drive comprises the authentication feature which uses the specified storage area on the disk as a hidden storage area and restricts accesses to the hidden storage area. Normally, the hidden storage area stores key information needed for encryption/decryption processing. This key information is used for encrypting or decrypting content data stored in a normal storage area without access restrictions.
Generally, the authentication method employed for conventional memory cards etc. uses one type of authentication process to enable or disable accesses to the hidden storage area. Since the memory card has a limited storage capacity, the hidden storage area is also limited. Normally, a single authentication process is sufficient for the authentication method.
However, a disk drive has a large storage capacity. It is possible to provide a plurality of hidden storage areas on the disk. If different authentication methods can be assigned to respective hidden storage areas on the disk, it is possible to improve the security feature for the entire disk drive.
It is an object of the present invention to provide an effective security feature for a plurality of hidden storage areas on the disk and improve the security feature for the entire disk drive.
In accordance with one aspect of the present invention, there is provided a disk drive including an authentication system for access control to hidden storage areas in a disk.
The disk drive comprises: a disk storage medium having a plurality of access limited hidden storage areas other than a normal storage area; a controller which, in response to a request to access each of the hidden storage areas from an external system, performs authentication processing for determining access permission for each of the hidden storage areas by using specific authentication information defined for each of the hidden storage areas; and a read/write mechanism which performs a read/write operation for the disk storage medium under control of the controller and performs a read/write operation for each of the hidden storage areas only when an access is permitted according to a result of the authentication processing.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.